<pre>  /**
   * The constants used in this Content Widget.
   */
  public static interface CwConstants extends Constants {
    String cwHorizontalPanelButton();

    String cwHorizontalPanelDescription();

    String cwHorizontalPanelName();
  }

  /**
   * An instance of the constants.
   */
  private final CwConstants constants;

  /**
   * Initialize this example.
   */
  @Override
  public Widget onInitialize() {
    // Create a Horizontal Panel
    HorizontalPanel hPanel = new HorizontalPanel();
    hPanel.setSpacing(5);

    // Add some content to the panel
    for (int i = 1; i &lt; 5; i++) {
      hPanel.add(new Button(constants.cwHorizontalPanelButton() + " " + i));
    }

    // Return the content
    hPanel.ensureDebugId("cwHorizontalPanel");
    return hPanel;
  }

</pre>